jacobs



March 10, 1925 R 16,019

E. H. JACOBS SWITCH I Original Filed Dec. 18'. 1918 65 Ernagi J-[ JawsReissued Mar. 10, 1925.

fuNITaoLsfrArEs PATE T OFFICE.

nmymsr It. means, orflcmoae 0, 'I Lmo-Is, assIGnoR To ELECTRICALENGINEERS EQHDMENT COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OFILLINOIS.

' I swn'cn.

- original Io.j1,878,155, dated April 19,1921;

. rei e'nl'cd July 26, 1922., Serial No. 577,763.

To all it v Be it EnnasrH. Jaconsl a find: State of vA new and use haofjwhich the 5,1 Incise, and exact descri'ptrp ca being had to theaccompanying dr g. fanning apart of lothisspecificationri My inventionlatesto mprovements in switches; for'fo i ng'and closing electrical meatof electric l5 p'owef jtransmisslon which leads to :min'y circuitscarryinglarge quantities offrent and 'alsothejhigh cost of materials;

I ntinu'es tjo' 'enfor'ce economy in sizes of contact and switches, andalso inthe quantltv 10f materialfifusedayvith the; that in {the oldstyle spring contact switches do not present contact capacity suf-'ficient' toprevent overheating. This situa-'- tion hasycreated a demandfor'a-swit'ch'of 26 minimumflimensions and low cost. as tomaterials,f'arid one of maximum current carryingcapacity relatively tothe dimensions and jbl'naterial used.

v 'Thjeohject of the present invention is to Y 3 provide aswitch of thechar'acter above outlined which .shall provide maximum coopcratingcontacting surfaces. relatively to the sizeof the switch, which shallconsist of a minimum number of parts. andin which the l blades shallcomprise bars formed of straight bars of metal and formed to providecontact-.

ing spacing parts or shoulders for maintaining the bladesspacedsubstantially, the thickness of Y the contacts with which the blades.

cooperate.

' -'-L;M invention will be more readily underby-reference to saiddrawinlzs in which -'Figure 1 is;i top plan view of the switch-,in.:closcd f tion gfi a-F'g; 2 side elevation of the'switch;

Fig.8 is aperspective view of one of the corlitact memlfr ers; and l i.4isa ra nta to' panviewoa modi lied fonno f gvitch bar so The switchcomprises two'metal contacts [1 and 2' each mounted upon the top of aninsulator 3.

a suitable base"plate; 4 by meansf o f metal 7 gstandards 5 which arcsecured upon the top tatesfresiding in wiser Each vided with members. 1These insulators are fixed upon" surface-of the base 4 by screws 6.These standards project up within the insulators and are secured theretoby cement or other suitable means. h

. The metal'contact 1 and 2'comprise an electrical contact which; is'formed to provide flat contact surfaces 7 at their opposite sides. Thesesurfaces of the two contact members are intended to lie in two parallelplanes, but it is readily understood that when they are built up oninsulators, as describedfithey may not be. truly parallel, parallelismwhich my improvement is intended to minimize, in so far -as it wouldtend to destroy proper maximum contacting surfaces. provided with toenter within upon which it ismounted and is adapted to be held rigidlytherein by cement or otherof the contacts 1 and 2 is proa-horizontalb'ase projection 9 to which a suitable-terminal 10 can be secured, as byboltsll' for securing a conductor'to the contact member. e The switchbar-for electrically. connecting the contact members 1 and 2 comprisestwo substantially parallel blades 12- and 13 made from straight bars ofmetal. These blades are as wide as the contacts 7 are high and arerelatively thin so that they are adapted to yield,. to some extent, toaccommodate themselves to lie flat against the surfaces 7, At one end ofthe switch bar'the blades are pivotallymounted upon the contact memer 1bya bolt 14 which passes through the two blades and through a centralaperture which I provide in the member 1 I yieldingly hold the bladesagainst the side of the contact member 1' by spring washers 15 and 16wh'ich I provide on the bolt1'4 and which -areheld against the 12 and 13by the head of the bolt and'the nut-i part at thei r upper ends and itis this lack of true- Each of the members 1 and 2 is a bottom projection8 adapted the upper end of the insulator outer sides of the bladesSerial No. 267,374, filed December 18, 1918. Application for 17 at theopposite end-of the bolt.' Each of y radial saw cuts 18. It will beunderstood that other spring'means may be employed the blade against thecontactfor holding The opposite'ends of the blades areofiset or benttoward each other; as at. 19, to bring the adjacent faces into contactto hold the member 2, against which the lower edges of member 2.

In the preferred form of my invention I hold the two blades yieldinglytogether by two bolts 20 and 21 similar to the pivot bolt 7 14 andarranged to span the outer contact member 2, and I yieldingly hold thetwo blades toward each other as by spring washers on the bolts 20 and21, similar to the spring washers 15 and.16 on the pivot bolt. Forswinging the switch blades on their pivots for opening and-closing eachswitch I provide the switch blade with a hole 23' in its free endadapted to receive a hook or some similar tool for moving the blades. I

rovide this holeby providing openings in the two blades which registerwith each other when the blades are assembled as described, the severalbolts serving blades in'relative position. I .ofi'set ends of the bladesare in contact the bladesare spaced apart slightly less than the{thickness of the contact 2, sqthat as the switch bar is closed upon.the contact 2, the against the blades are wedged slightly apart springressure. Even when the ends of the bla es are held against separationthey are not permanently distorted by being thus spread apart as theyarethin enoughto permit this spreading action and I bevel the free end 24of the contact 2 to permit the easy insertion of the contact between theblades. In order to limit the closing movement of the switch bar andalso to provide additional contacting surfaces, I provide lateralshoulders 25 on the sides of the contact the blades contact when incircuit closing position. These shoulders are preferably arranged to setthe switch bar parallel with the base when completely closed.

It will nowibe clear that the two blades are adapted to lie flat againstthe faces 7 of the contact members even though these faces are not intrue alinement, that consequently the switch provides maximum contacting surfaces relatively to the dimensions of the parts, and that theoffset ends of the blades serve as spacers to hold the blades spaced farenough apart to receive the contact member 2 between them.

I In the iorm of my invention illustrated in Fig. 4, I have eliminatedthe spring means for yieldingly holding the free ends of the bladestogether, relying upon the resiliency of the blades themselves for thisfunction, and holding them against separation by the bolt 26, spaced ashort distance from the inner edge of the contact member 2' and somemeans for tying the outer ends of the blades togethensuch asthe tubularrivet 27. .As in the first-form I provide the outer ends of the twoblades 28 and to hold the Vhen the two 29 with registering openings andI utilize this opening 'for the tubular rivet 27. I

secure the r1vet27 in position by turning .its ends over to contact withthe outer surfaces of the blades. I preferably use a tube of relativelylarge diameter for the purpose of providing the the hole 23 forreceiving a hook with which to operate the switch. I may hold the endsof the blades tightly clamped together by the rivet 27, but this is notabsolutely neces sary. As explained, the resiliency of the bladesthemselves is depended upon to permit' the switch bar as a whole toyield when closing the bar upon the contact 2, the blades being heldtogether slightly closer than the thickness of the contact member.

As many modifications of my invention switch bar with will readilysuggest themselves to those skilled in the art, I do not intend that Ishall be limited'to the specific structures or arrangements herein shownand described.

I claim:

1. In an electric switch, the combination ofa rigid stationary contactmember, a pair of separate flexible blades lying on the opposite sidesof said member, a bolt passing through said blades and said member forpivotally mounting said blades thereon, spring means for 'yieldinglyholding the blade in contact with the sides of said member, a secondstationary contact member spaced from the first member. said bladesadapted to be swung on saidbolt to contact with the sides of said secondcontact member, means yieldingly holding said blades toward each otherfor contact with said second contact member, the free ends of saidblades being offset inwardly to contact with each other for spacing saidblades in substantiallv parallel relation, the

free ends of said blades having aligning I v openings for swinging themsimultaneously on said pivot for opening or closing the switch, saidfree ends having lateral play to permit the blades to adapt themselvesto the-sides of the second contact meniber. v

2. In an electrical switch, the combination of two. stationary contactmembers having oppositely disposed contact surfaces lying substantiallyin parallel planes, a

switch bar. comprising two separate relatively thin flexible bladesformed from'j get'iier but permitting them to yield laterally to permitthe entrance, of said other contact member between them, the offsetendsv which are in contact having registering transverse openings toreceive an operating hook. v

3. In a switch, a switch blade comprising duplicate flexible barsarranged back to back, said bars having each an outer offset end inparallel engagement for spacing the adjacent portions of the bars apart,said ofiset ends having registering openings therethrough for forming anoperating eye, said bars having registering pivot'openings at theopposite end for receiving a pivot bolt and also having registeringopenlugs intermediate said other openings for receiving a bolt forholding the blades 130- Ward each other.

Iii-testimony whereof, I have hereunto subscribed my name this 21st dayof July, 1922.

fERNEsT H. JACOBS.

